Error when assigning different author on back end

I had a member post in blogs when should have been discussions. I cant find a way to create a discussion on back end, so had admin create discussion on front end (which then sends out email as admin is author... having ability to create discussion on backend and assign author would be a great feature.).

I then went to back end to edit the discussion and assign the approriate author. I was able to choose the author, but when I went to save I received the following error (note, I did later change the author through the database)

Catchable fatal error: Argument 1 passed to plgFinderEasyDiscuss::index() must be an instance of FinderIndexerResult, instance of stdClass given, called in /home/XXXXX/public_html/administrator/components/com_finder/helpers/indexer/adapter.php on line 333 and defined in /home/XXXXX/public_html/plugins/finder/easydiscuss/easydiscuss.php on line 103